Opened 11 years ago

# Categories for finite (enumerated) sets

Reported by: Owned by: Nicolas M. Thiéry Nicolas M. Thiéry major sage-9.8 categories Sage Combinat CC user, Simon King, Andrey Novoseltsev N/A #12913

### Description (last modified by Frédéric Chapoton)

There still remains a lot of finite (enumerated) sets that are not in the appropriate categories::

```sage: LatticePolytope(matrix(ZZ, [[3,0],[0,3]])).points().category()
Category of objects
```

The following examples were originally in the ticket description but are good on sage-6.9.beta1

```sage: Permutations().category()
Category of infinite enumerated sets
sage: DirichletGroup(5).category()
Category of finitely generated finite commutative groups
```

Moreover, with Sage 7.4.beta0 we now have:

```sage: CartesianProduct([1,2],[2,3]).category()
... DeprecationWarning: CartesianProduct is deprecated. Use cartesian_product instead
See http://trac.sagemath.org/18411 for details.
#!/usr/bin/env python
Category of Cartesian products of finite enumerated sets
sage: cartesian_product([[1,2],[2,3]]).category()
Category of Cartesian products of finite enumerated sets
sage: Set([1,2,3]).category()
Category of finite sets
```

Formerly not working, ok in sage 9.3.b6:

```sage: Set([1,2,3]).category()
Category of finite sets
sage: (GF(3) ^ 2) in FiniteEnumeratedSets()
True
sage: MatrixSpace(GF(3),2) in FiniteEnumeratedSets()
True
```

### comment:1 Changed 9 years ago by Jeroen Demeyer

Milestone: sage-5.11 → sage-5.12

### comment:2 Changed 9 years ago by For batch modifications

Milestone: sage-6.1 → sage-6.2

### comment:3 Changed 9 years ago by For batch modifications

Milestone: sage-6.2 → sage-6.3

### comment:4 Changed 8 years ago by For batch modifications

Milestone: sage-6.3 → sage-6.4

### comment:5 Changed 7 years ago by Vincent Delecroix

Description: modified (diff)

On sage-6.9.beta1 things get better... I modified the description accordingly

Last edited 7 years ago by Vincent Delecroix (previous) (diff)

### comment:6 Changed 6 years ago by Matthias Köppe

Cc: Andrey Novoseltsev added modified (diff) sage-6.4 → sage-7.4

I have updated the description with the status as of version 7.4.beta0.

Regarding `LatticePolytope` (one of the examples in the description), I would be reluctant to consider it a finite enumerated set. There should be a distinction between the lattice polytope (an infinite set) and the set of its lattice points. The latter (which also makes sense for non-lattice polytopes) should be made a finite enumerated set.

### comment:7 Changed 23 months ago by Frédéric Chapoton

Description: modified (diff)

### comment:8 Changed 23 months ago by Frédéric Chapoton

Description: modified (diff) sage-7.4 → sage-9.4

### comment:9 Changed 23 months ago by Frédéric Chapoton

Description: modified (diff)

### comment:10 Changed 16 months ago by Matthias Köppe

Milestone: sage-9.4 → sage-9.5

### comment:11 Changed 12 months ago by Matthias Köppe

Milestone: sage-9.5 → sage-9.6

### comment:12 Changed 8 months ago by Matthias Köppe

Milestone: sage-9.6 → sage-9.7

### comment:13 Changed 3 months ago by Matthias Köppe

Milestone: sage-9.7 → sage-9.8
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